If you belong to a bird club ask other members where they take their birds, who do they like, who to stay away from. Bird club member normally LOVE to share the best information about parrots for others parrot owners.
If not doing internet research might give you some names of clinics with the names of the doctors who practice avian medicine but it is always a gamble to know if they are any good at it.
I might move to Iowa City for a job opportunity if offered the position. In my case I did the research and found one clinic with an avian vet. I will also refer to Valentino's doctor and ask if she has any recommendations for avian vets in the Iowa City area. I know Dr. Blair does attend many conferences and knows avian vets from all over the world so I would trust her recommendation for a good avian vet in the new town I might have to relocate too.
Good luck finding a capable knowledgeable avian vet in your area. When you do find a good one give a shout out to the clinic and doctor you decide to use and why you like them.